This application relates to features of a combined lower bearing mount and a lower housing end cap in a compressor. In particular, structure on the lower end cap facilitates the alignment housing of an outer shell housing on the lower end cap.
Scroll compressors are becoming widely utilized in refrigerant compression applications. In a scroll compressor, first and second scroll members each have a base and a generally spiral wrap extending from their bases. The wraps interfit to define compression chambers. One of the two scroll members is caused to orbit relative to the other, and with the orbital movement the size of the compression chambers decreases. An entrapped refrigerant is then compressed.
A shaft is driven by an electric motor, and operates through a connection to cause the scroll member to orbit. The shaft is mounted adjacent a lower end of the housing on an opposed side of the motor relative to the pump unit.
Typically, the lower bearing is mounted from a center shell housing, and extending radially inwardly. More recently it has been proposed to mount the bearing on an end cap which defines a lower end of a sealed housing. Typically the housing for the scroll compressors include a center shell extending generally along the rotational axis of the shaft and having upper and lower end caps.
In one known type of scroll compressor, the end cap has an upwardly extending generally u-shaped structure positioned slightly radially inward of the inner periphery of the center shell. The center shell is then welded to that end cap. The prior art has had this u-shaped structure extending around the entire circumference. With such a structure, there has sometimes been alignment difficulties with regard to aligning a seam which is found extending along the axial length of the center shell, and is part of the formation of the center shell. The seam creates a discontinuity at the weld joint between the shell and the lower end cap. Moreover, the center shell has typically been placed around the outer periphery of the u-shaped circumferentially extending portion, and the circumferentially extending portion has generally had a small angle to facilitate this connection.
In the disclosed embodiment of this invention, the lower end cap is formed with circumferentially discontinuous and spaced u-shaped portions. The spacing between these portions facilitates the alignment of the center shell on the lower end cap. Specifically, the gaps between the u-shaped portions provide a space to which the seam can be aligned. Moreover, in the present invention, the outer periphery of the spaced u-shaped portion is machined such that the center shell is positioned at a location spaced by an idealized distance from the location of a bearing. That is, with this invention the end cap can be ideally positioned relative to the center shell, and relative to a lower bearing mounted to the lower end cap. In this way, the alignment of components within the compressor is improved compared to the prior art. Various embodiments of the u-shaped section are disclosed.
These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description.